Crosswalks are a means of allowing pedestrians to cross streets at designated locations with comparative safety. At street intersections, pedestrians are usually assisted in crossing the street by the traffic control signage or signal equipment, which may include “WALK”, “DON'T WALK” lighted signs, or the analogous iconographic lighted signs, linked to the traffic light system.
At ‘mid-block’ locations remote from intersections, crosswalks are usually indicated by white lines on the pavement and signage to show the location of the crosswalk. Pedestrians wanting to cross the road must stand on the side of the road at the start of the crosswalk to indicate their intention to cross the road, and drivers are expected to notice the pedestrians, stop and allow them to cross.
In darkness, where traffic levels are higher, or on multi-lane roads this minimal kind of crosswalk is not effective because drivers may not see the pedestrians waiting at the crosswalk, or may ignore them. Furthermore, pedestrians may feel empowered to cross the street when in fact they have not been noticed by the motorists. Fatalities at crosswalks are relatively common, and have caused crosswalks to be regarded as a serious safety issue. However, the alternative to crosswalks is to have no regulation of pedestrians crossing busy streets, and this is a worse alternative.
In order to improve safety at crosswalks, a number of strategies are in use. Since the danger is most pronounced at night, crosswalks are sometimes lit with overhead lighting. This is an expensive solution due to the costs of bringing electricity to the crosswalk, installing the overhead lighting across the road, and providing maintenance and electricity to the site.
Another strategy is to install flashing yellow warning signals at crosswalks so drivers notice the crosswalk and slow down, thereby improving their chance to see pedestrians using the crosswalk. These flashing signals are cheaper and easier to install than full-fledged lighting systems, and have lower on-going costs. However, since neither of these solutions is activated by the pedestrian, drivers learn that most of the time crosswalks are not being used, and they ‘tune out’ the crosswalk, and do not notice if pedestrians are present.
Another type of system which improves safety in crosswalks is described in our co-pending application Ser. No. 10/475,574. This system comprises a solar-powered warning light system on a timer, so warning lights activate automatically at specific times. This kind of assembly can be very useful at crosswalks adjacent to schools. Posted signs require that traffic slow down when the warning lights are flashing to a slower speed limit. The combined effect of the flashing lights and the reduced speed limit improves safety at crosswalks, while only slowing traffic during specific times. This strategy is effective only when the pedestrian traffic usage of a crosswalk can be predicted, such as the timing of students going to and from school.
Compared with these strategies, active warning systems provide the highest degree of driver awareness and pedestrian safety. Active crosswalk systems are systems that are activated by the pedestrian to warn drivers that the pedestrian wants to cross the road.
U.S. Pat. No. 6,268,805 discloses a solar-powered traffic light and LED light sources. In order to be used at a crosswalk, this system would require trenching or wiring to connect the traffic lights on each side of the road for coordinated activation.
U.S. Pat. No. 6,384,742 discloses a traffic warning system which alerts approaching vehicle traffic to the presence of a pedestrian in a crosswalk. The system includes a plurality of surface mounted lights partially embedded in and placed across a roadway to delineate the crosswalk. This system requires trenching of the road and power from the electricity grid.
U.S. Pat. No. 5,734,339 discloses a crosswalk warning light system which detects a pedestrian entering the crosswalk and activates a light which illuminates the pedestrian so a driver can see and avoid the pedestrian in the crosswalk. This solution requires power from the electrical grid.
Accordingly, an object of the present invention is to provide a crosswalk warning system that can be installed in any desired location without requiring power from the electrical grid and without requiring trenching of the road or overhead wiring such as would normally be required to coordinate the signal lights on each side of the road.
Another object of the present invention is to provide an ‘active’ crosswalk warning system in which a pedestrian can activate warning beacons prior to using the crosswalk.
Other objects of the invention will be apparent from the summary and the detailed description that follows, and not all such objects are necessarily simultaneously achieved for the principal embodiment of the invention or for each claim of this patent.